Sheet conveying apparatus



July 28, 1964 R. W. COLE SHEET CONVEYING APPARATUS 2 Sheets-Sheet 1 Filed Dec. 18. 1961 N ms I M a @QX 1 INVENTOR. ROBERT W. C0\ E @fTo/WEY July 28, 1964 R. w. COLE SHEET CONVEYING APPARATUS 2 Sheets-Sheet 2 Filed Dec. 18, 1961 INVENTOR. ROBERT W COLE W ATTORNEY United States Patent 3,142,388 SHEET QQNVEYING APPARATUS Robert W. Qole, Menasha, Wis., assignor to Menasha Wooden Ware (Iorporation, Menasha, Wis., a corporation of Wisconsin Filed Dec. 18, 1961, Ser. No. 152,998 4 Claims. (Cl. 214-6) This invention relates to apparatus for conveying suc cessive stacks of sheets wherein alternate stacks are by this apparatus placed in inverted position. The invention is particularly useful in connection with the manufacture of corrugated cartons, such as shipping containers or fibers.

In the manufacture of corrugated paperboard shipping containers, sheets of corrugated board are first carried through a machine which cuts and creases the board in a predetermined fashion for subsequent erection into the desired carton or container. The cut and scored sheets, which provide the container blank from which the container or carton is erected, are delivered from the cutting and scoring machine in a shingled succession of blanks, a number of such consecutive sheets being stacked into individual stacks of predetermined height, usually five to six inches. As the sheets have a marked tendency to warp or curl, it is customary for such stacks to be placed together in a pile, with alternate stacks inverted or upside down to combat the tendency of the sheets to warp. However, since the sheets from such piles are customarily printed or otherwise handled in a way requiring presentation of the same surface of all sheets in such subsequent operations, it is necessary that there be some means of determining which of the small stacks have been inverted with respect to the other stacks. In normal practice, these small stacks are piled by hand with the alternate stacks being offset to provide ready identification of those stacks which have been inverted. This operation requires substantial amounts of expensive and time-consuming manual labor and it has long been the goal to provide mechanical means which will perform this function.

The purpose of this invention is to provide an apparatus which will receive successive shingled sheets from the corrugated board cutting and scoring machine, position them in small stacks of predetermined size, and transfer these smaller stacks to a conveyor or station in such manner that alternate stacks are in inverted position, and with alternate stacks being placed on the subsequent conveyor or station in an offset position with respect to the other smaller stacks, this all being done without the interposition of manual effort.

Other more specific objects and advantages of the present invention will become apparent from the following description in connection with the appended drawings, in which:

FIGURE 1 is a plan view, partially cut away, of the main elements of a preferred embodiment of the invention,

FIGURE 2 is a cross-sectional view, taken along the line 2-2 of FIGURE 1, showing in phantom lines a second position of a part of the apparatus,

FIGURE 3 is a perspective view, partially cut away, of the main conveyor and associated elements combining a principal part of the invention,

FIGURE 4 is a perspective view, partially cut away, of a truck upon which alternate offset stacks of sheets may be stacked by the apparatus comprising the invention.

Referring first to FIGURES 1 and 2, the invention includes a main frame It) and pairs of supporting stanchions 11 and 12, only the more distant stanchions of each pair appearing in FIGURE 2. A first conveyor indicated generally at 20, having supporting side frames 21, is supported on the upper ends of stanchions 11 and 12. Shafts 22, 23 and 24 are rotatably journaled in side frames 21, in

bearing housings 25, 26 and 27, respectively. Shaft 22 has keyed thereto a series of spaced pulleys 3t), and similarly, a series of correspondingly spaced pulleys 31 are mounted on shaft 24. Corresponding pairs of pulleys 38-31 carry a series of spaced conveyor belts 35. Belts 35 are driven at a predetermined speed, in the direction indicated by the arrows in FIGURES l and 2, by conventional means connected to either shaft 22 or shaft 24, such as an electric motor indicated at 36 geared to shaft 22.

A series of spaced auxiliary frame members 39 is keyed or otherwise fixed to shaft 23, each of members 39 having a flipper finger 40 pivotally mounted thereon as at 41. A driven pinion or gear 42 is keyed to shaft 23 intermediate its ends, and is driven by a rotatable pinion 43 journaled in a supporting bracket 44. Pinion 43 is in turn driven or activated by a rack 45 actuated by a cylinderpiston assembly 46 mounted on frame 10. Assembly 46 is preferably actuated by a controlled conventional pressure air supply system, though, as will be seen, pinion 43 may be actuated by any suitably controlled conventional power means.

A cylinder-piston assembly 49, preferably air-actuated, is at one end pivotally connected at 50 to a bracket 51 on each of fingers 40, at the other end being pivotally connected at 52 to a bracket 53 on the associated auxiliary frame member 39. The function and operation of the mechanism thus far described will be set forth in detail in connection with the description of the operation of the complete apparatus.

A stop 54 is pivotally mounted at 55 intermediate its ends at the end of each of fingers 40. A cylinder-piston assembly 56, preferably air-actuated, is at one end pivotally connected at 57 to the lower end of each of stops 54, and at the other end pivotally connected at 58 to the associated auxiliary frame member 39. Actuation of as semblies 56 to force their associated piston rods outwardly obviously will result in clockwise (FIGURE 2) rotation of stops 54.

A series of chains 60 is mounted in conveyor 20, the chains being driven by pinions 61 keyed to driven shaft 62, and being supported by pinions 63, idler gears or pinions 64, and guide or channel members 65. Shaft 62, and pinions 63 and 64, are suitably journaled in the frame of conveyor 20, and channels 65 are also suitably supported thereby. Shaft 62 is driven by a suitably controlled (as explained later herein) reversible electric motor 78, to which it is connected by pinion 71 on the motor shaft, chain 72, and pinion 73 keyed to shaft 62. Each of chains 68 has a stacking finger 74 mounted thereon adjacent the infeed end of conveyor 20.

A second conveyor 75, mounted on stanchions 76 and 77, is positioned adjacent the delivery end (the right end as seen in the drawings) of conveyor 20. This conveyor is basically similar to conveyor 20, and includes side frames 78, rotatable shafts 79 and 80 with keyed pulleys 81 and 82, respectively, carrying driven conveyor belts 83.

A sheet stack oifsetter is mounted on conveyor 75, comprising a pair of levers 85 pivotally mounted to the conveyor frame at 86, and having a pair of offsetting pads 87 fixed to vertical extensions 88 at their remote ends. The other ends of levers 85 overlap and are slotted at 89. A cylinder-piston assembly 90, preferably air-actuated, is mounted to the frame of conveyor 75, the piston rod extension 91 having a pin 92 which rides within slots 89. As assembly 20 is actuated to extend the piston, pin 92 rides Within slots 89 (in the downward direction as seen in FIGURE 1), causing levers 85 to rotate oppositely about pivots 86 to force pads 87 toward the center of the conveyor (upwardly in FIGURE 1) to the position shown in phantom in FIGURE 1. Belts 83 are driven in the direction of the arrows by a suitably controlled source of ice power, such as an electric motor indicated at 93 connected to shaft 80.

At the delivery end of conveyor 75 there may be positioned a further conveyor 95 or other means for receiving stacks of sheets from conveyor 75. These additional means comprise no part of the present invention, and so are not described further.

The delivery end of the conventional cutting and creasing machine includes a conveyor, indicated at 100, which in its more basic elements corresponds to those previously described. Specifically, conveyor 100 includes side frames 101 and shaft 102 having keyed pulleys 103 supporting driven belts 104. The present invention contemplates, in addition to the foregoing novel structure, the addition of certain mechanism to conveyor 100. Specifically, brackets 107 are fixed to the frame of the conveyor, and a shaft 108 is journaled therein. Shaft 108 has a series of stop fingers 109 fixed thereto in positions be tween belts 104. Also fixed to shaft 108 is an arm or lever 110, to the end of which is pivotally connected one end of a cylinder-piston assembly 111, preferably airactuated. The other end of assembly 111 is pivotally connected to a bracket 112 on the frame of conveyor 100. Actuation of assembly 111 to move the piston rod 113 from a withdrawn to an extended position results in pivotal movement of fingers 109 from a position below the upper reach of belts 104 to a position where the remote ends of the fingers are substantially above the plane of the upper reach of the belts.

The various elements of the mechanism described are associated, driven, and controlled together by conventional means to produce the operation now to be described.

Sheets A (FIGURE 2) of material to be handled, such as sheets of corrugated paperboard from a cutting and creasing machine, are carried in shingled formation by conveyor 100. In an initial position of the apparatus of the present invention, piston rod 113 is in a withdrawn position, so that levers 110 and fingers 109 are in the position shown in phantom lines in FIGURE 2. Likewise, motor 70 has driven chains 60 to position fingers 74 as shown in phantom lines, below the line of movement of sheets A from conveyor 100 onto conveyor 20. In this phase of the sequence of operation, cylinder-piston assembly 56 is actuated to withdraw its associated piston rod, so that stops 54 are in the upright position shown in full lines in FIGURE 2.

Belts 35 are driven at a substantially faster linear speed than belts 104, so that conveyor 20 tends to carry sheets A away from conveyor 100. Further, conveyor 100 is driven at a speed suflicient to give sheets A a positive momentum for deposition onto conveyor 20.

Stops 54, being in upright position, prevent belts 35 from carrying sheets A beyond their position, even though belts 35, as well as belts 104, are continuously driven. Delivery of sheets A to conveyor 20 continues until a predetermined number of sheets has been delivered onto conveyor 20. This may be determined, for example, by a conventional counter mechanism, although for certain reasons it is preferred to deliver sheets until a stack B of sheets of predetermined height has accumulated. This selected and predetermined stack height may be controlled by a conventional detector mechanism 120 mounted on one of stops 54.

When the stack B of sheets on conveyor 20 reaches the predetermined height, detector 120 is actuated. By conventional interconnected control means, pressure air is directed to cylinder-piston assembly 111 to retract piston rod 113 and thus raise fingers 109 to the full-line position of FIGURE 2. This movement of fingers 109 lifts sheets A from belts 104 sufliciently to prevent the belts from conveying additional sheets onto conveyor 20.

Immediately thereafter, motor 70 is actuated to drive chains 60 to carrying stacking fingers 74 from the phantom to the full line positions shown in FIGURE 2, this action squaring stack B as shown. The drive for motor 70 includes a conventional pressure-responsive control, which may be set to deliver a predetermined quantum of pressure or force to fingers 74, sufficient to cause alignment of stack B, and upon the control building up to this pressure or force an automatic reversal of motor 70 is caused, to return fingers 74 to the position shown in phantom lines in FIGURE 2.

The return of one of fingers 74 to the original position actuates a limit switch 121, mounted on one of channels 65, which controls the source of pressure air to cylinderpiston assemblies 46 and 49, directing pressure air to extend these assemblies. The extension of assembly 46 drives rack 45 to the right as seen in FIGURE 2, which through the gear train 43, 42 results in clockwise rotation of shaft 23 and auxiliary frame members 39 to carry flipper fingers 40 to the position shown in phantom lines. The actuation of assembly 49 merely gives an additional clockwise pivotal movement to flipper fingers 40, for the purpose of more readily presenting stack B (carried by the flipper fingers) in a flat and inverted position onto conveyor 75 as seen in FIGURE 2. If sufficient travel of auxiliary frame members 39 can be obtained through assembly 46 and its associated elements, without the addition of assembly 49, in order that stack B may be presented substantially flat onto conveyor 75, assembly 49 may be eliminated. Assemblies 46 and 49 must, of course, be actuated with sufficient speed to cause the inversion of stack B onto conveyor 75 without the force of gravity causing the individual sheets in the stack to drop away from fingers 40, which happenstance would tend to produce unevenly aligned stacking on conveyor 75. Immediately upon reaching the position shown in phantom lines in FIGURE 2, cylinder-piston assemblies 46 and 49 are by conventional controls automatically reversed in their action to return frame members 39 and flipper fingers 40 to their original position. For example, upon complete extension of rack 45 a pin 126 thereon actuates limit switch 125 on frame 10 to cause reversal of assemblies 46 and 49. Either by preferred and conventional time sequence controls, or by a limit switch 130 on conveyor 20 or other conventional means, the return of flipper fingers 40 to their original position controls cylinder-piston assembly 111 to withdraw piston rod 113 and thus retract stop fingers 109 to the phantom line position of FIGURE 2, thus permitting sheets A to be carried again onto conveyor 20.

As the rack 45 reaches its fully extended position, with flipper fingers 40 in the ultimate position shown in phantom lines, in which the stack B is deposited onto conveyor 75, the actuation of limit switch 125 by pin 126 also directs the source of pressure air to cylinder-piston assembly to extend the piston and thus drive offsetting pads 87 to the phantom line position shown in FIG- URE 1. The apparatus is set up to deliver stack B onto conveyor 75 in such position that the adjacent edge of stack B is immediately proximate the original full line position of pads 87, so that this actuation of pads 87 results in a displacement of stack B on conveyor 75 to a somewhat upwardly position as seen in FIGURE 1. Continuously driven belts 83 on conveyor 75 deliver the offset stack onto the further conveyor or any other receiving means, from which a resulting pile of alternate offset stacks may eventually be taken for further manufacturing operations or other disposition. Upon reaching its preset limit of travel, cylinder piston 90 automatically reverses to return pads 87 to their original full line position.

Stop fingers 109 having been depressed upon the return of fingers 40 to their inactive position, as previously disclosed, sheets A again are conveyed onto conveyor 20, where they are restricted from further travel by stop fingers 54. When the new stack B thus being formed reaches predetermined height, actuation of detector again occurs resulting in power being applied to motor 70 and to cylinder-piston assembly 111 to drive fingers 74 to align the new stack B and to raise fingers 109 to stop further conveyance of sheets A, in the manner previously disclosed. Again, motor 70 automatically reverses to return fingers 74 to the phantom line position of FIGURE 2. However, in this alternate sequence, the actuation of limit switch 121 does not result in actuation of assemblies 46 and 49, but instead results in the direction of pressure air to assembly 56. This causes assembly 56 to extend, and thus to rotate fingers 54 clockwise to the phantom line position of FIGURE 2, where they no longer interfere with the travel of the stack B. Continuously driven belts 35 of conveyor 2t then convey the new stack onto conveyor 75 and thence onto conveyor 95 or the means alternative thereto. It will be obvious that this new stack B has not been inverted and further, there will have been no actuation of the offsetting pads 87 to offset this new stack B with respect to its original position on conveyor 75.

The passage of the trailing end of this new stack B of sheets beyond a micro-switch 131 mounted on conveyor 2t) (FIGURE 2) actuates the switch to result in the powering of cylinder-piston assembly 56 to retract the piston and raise fingers 54 to the full line position, and simultaneously actuates cylinder-piston assembly 111 to retract fingers 109 to again permit sheets A to be conveyed onto conveyer 20. The total apparatus is then in the initial position as first described and the total alternate sequence will then be repeated, this repetition of alternate steps continuing automatically without human intervention.

The various controls and connections necessary to actuate the mechanical devices to produce the sequence of operations described are conventional and need not be described in detail. A master control box 135, containing the necessary electrical controls, pressure-air pumps, valves and the like is indicated in FIGURE 2. schematically shown also are the pressure-air lines 136, 137, 138, 139 and 140 respectively leading to cylinder-piston assemblies 111, 49, 56, 46 and 90; also electrical connections 141, 142, 143, 144, 145 and 146 respectively extending to and connected with motor 70, detector 120, and switches 121, 130, 131 and 125.

FIGURE 4 shows in part a conventional wagon or cart 150 which might be substituted for the conveyor 95 partially indicated in FIGURE 2, and upon which the alternately offset stacks B from conveyor 75 would be delivered. As seen in FIGURE 4, stacks B are those first delivered onto conveyor 75 in the total sequence of operations described above, that is, those stacks which are carried onto conveyor 75 in inverted position by fingers 40 and offset by ofisetting pads 87. Stacks B" are those delivered in the second part of the sequence described, that is those stacks which are carried directly from conveyor 26 onto conveyor 75 without the functioning of fingers 40 and without offsetting.

It will be obvious that many modifications and variations might be incorporated into the invention as described without departing from its spirit. For example, fingers 54 may be commonly connected and powered by single cylinderpiston assembly or other mechanical or electrical device. The positioning of the various switches, such as switches 121, 130, 131 and 125, may be changed to other locations to achieve the objectives set forth. Electrical drives with appropriate conventional actuating means could readily be substituted for the cylinder-piston assemblies considered to be preferable, without significant change in the basic operating characteristics of the apparatus. Further, the offsetting mechanism comprising elements 35 to 90 could be mounted on conveyor 20 rather than conveyor 75, and the offsetting action may be coordinated to operate on either the inverted (or to be inverted) stack or on the alternate stack which is not (or is not to be) inverted. Therefore, it is to be understood that limitation on the scope of the invention is intended only as set forth in the appended claims.

I claim:

1. Apparatus for conveying stacks of paperboard sheets comprising a first conveyor, first means associated with said conveyor and mounted for pivotal movement about a point adjacent one end thereof, second means for inducing such pivotal movement in a vertical plane from an initial position substantially coincident with said conveyor through a substantial arc to invert a stack of sheets on said conveyor and to place such stack in inverted position, a second conveyor positioned adjacent said one end of the first conveyor to receive such stack of sheets from said first means, stop fingers moveably mounted on said first means for selectively stopping the movement of sheets carried by said first conveyor, stacking fingers moveably mounted on said first conveyor for aligning into a uniform stack a succession of sheets positioned on said first conveyor, and offsetting means associated with said conveyors to selectively offset stacks of sheets.

2. Apparatus for conveying stacks of paperboard sheets comprising:

(a) a first conveyor adapted to receive successive of said sheets,

(b) a second conveyor positioned to receive stacks of said sheets from said first conveyor,

(0) a third conveyor adapted to transfer shingled sheets onto said first conveyor,

(d) first stop means mounted on said third conveyor adapted to selectively inhibit transfer of shingled sheets onto said first conveyor,

(e) second stop means associated with said first conveyor adapted to inhibit transfer of sheets therefrom,

(f) sheet stacking means mounted adjacent the infeed end of the first conveyor to selectively contact the trailing end of sheets transferred onto the first conveyor and move said sheets into an aligned stack,

(g) sheet transfer means associated with said first conveyor and positioned substantially coincident with the conveying surface thereof, said transfer means being mounted for pivotal movement about a point adjacent the outfeed end of the first conveyor,

(h) means for inducing pivotal movement of said transfer means in a vertical plane through a substantial arc to invert a stack of sheets positioned on the first conveyor and to position such inverted stack onto the second conveyor, and

(i) offsetting means associated with one of said first and second conveyors to selectively offset said stacks of sheets.

3. Apparatus according to claim 2, further including control and power means adapted to consecutively:

(a) actuate the second stop means to inhibit transfer of sheets from the first conveyor,

(11) actuate the first stop means, upon accumulation of a predetermined quantity of sheets on the first conveyor, to inhibit transfer of sheets onto the first conveyor,

(c) actuate the sheet stacking means to move such accumulated sheets into an aligned stack,

(d) actuate the sheet transfer means to invert such accumulated stack into position on the second conveyor,

(e) actuate the offsetting means to laterally offset said stack of sheets on the second conveyor and actuate the sheet transfer means to return said means to original position substantially coincident with the conveying surface of the first conveyor,

(f) actuate the first stop means to permit transfer of shingled sheets onto the first conveyor,

(g) actuate the first stop means, upon accumulation of a predetermined quantity of sheets on the first conveyor, to inhibit transfer of sheets onto the first conveyor,

(h) actuate the sheet stacking means to move such accumulated sheets into an aligned stack,

(i) actuate the second stop means to permit transfer of 7 8 such stack of sheets onto the second conveyor, and steps, to form a pile of such stacks alternate ones (j) repetitively carry out the foregoing steps. of such stacks being offset from such alignment with 4. A method of forming in an aligned operation a pile respect to the other stacks, to combat tendency of of sheets of material comprising: the sheets to curl while retaining identity of the (a) in a first position, assembling a first stack of a 5 inverted stacks with respect to the non-inverted predetermined quantity of said sheets, stacks. (b) inverting said stack of sheets and depositing them if g PQZ f i t, t k f h r t References Cited in the file of this patent c 0 set rng sa1 rs sac rom suc aignmen (d) in said first position, forming a second stack of a 10 UNITED STATES PATENTS predetermined quantity of said sheets, 610,491 Miehle P 6, 1898 (e) transferring said second stack without inversion 1 1 Wood 7, 1913 thereof onto said first stack in such alignment, and 2,862,426 Gaubeft 2, 1958 (f) thereafter consecutively repeating the foregoing 3,039,626 schl'einer 111116 19, 1962 

1. APPARATUS FOR CONVEYING STACKS OF PAPERBOARD SHEETS COMPRISING A FIRST CONVEYOR, FIRST MEANS ASSOCIATED WITH SAID CONVEYOR AND MOUNTED FOR PIVOTAL MOVEMENT ABOUT A POINT ADJACENT ONE END THEREOF, SECOND MEANS FOR INDUCING SUCH PIVOTAL MOVEMENT IN A VERTICAL PLANE FROM AN INTIAL POSITION SUBSTANTIALLY COINCIDENT WITH SAID CONVEYOR THROUGH A SUBSTANTIAL ARC TO INVERT A STACK OF SHEETS ON SAID CONVEYOR AND TO PLACE SUCH STACK IN INVERTED POSITION, A SECOND CONVEYOR POSITIONED ADJACENT SAID ONE END OF THE FIRST CONVEYOR TO RECEIVE SUCH STACK OF SHEETS FROM SAID FIRST MEANS, STOP FINGERS MOVEABLY MOUNTED ON SAID FIRST MEANS FOR SELECTIVELY STOPPING THE MOVEMENT OF SHEETS CARRIED BY SAID FIRST CONVEYOR, STACKING FINGERS MOVEABLY MOUNTED ON SAID FIRST CONVEYOR FOR ALIGNING INTO A UNIFORM STACK A SUCCESSION OF SHEETS POSITIONED ON SAID FIRST CONVEYOR, AND OFFSETTING MEANS ASSOCIATED WITH SAID CONVEYORS TO SELECTIVELY OFFSET STACKS OF SHEETS. 